Thread tension for shuttle



N V- 22, 19 A. CEDERLUND ErAL 2,961,008

THREAD TENSION FOR SHUTTLE Filed April 24, 1957 FlG.2

Fl G. 7

27 3| INVENTORS V V a 25 ALBERT GEDERLUND a 9 w 26 v I KENNETH J. HALLCLIFFORD DARWIN a W. 7M

ATTORNEY 2,961,068 7 Patented Nov. 22, 1960 AD TENSION FOR SHUTTLEAlbert Cederlnnrl and Kenneth J. Hall, Worcester, and Clzfiord Darwin,Paxton, Mass., assignors to Crompton 4i: Knowles (Iorporation,Worcester, Mass., 2 corporation of Massachusetts Filed Apr. 24, 19515.No. 654,806

7 Claims. c1. 139 217 This invention relates to improvements in tensionsfor self-threading shuttles for weft replenishing looms and it is thegeneral object of the invention to provide a shuttle tension whichcauses the first pick of the shuttle after replenishment to have thesame tension as the subsequent picks have.

In weft replenishing looms of the bobbin-changing type reserve bobbinsare held in some form of magazine provided with a thread holder for theweft ends which extend from the bobbin. At the time of a bobbin transferor Weft replenishing operation a reserve bobbin is pushed into theshuttle and on the first flight of the shuttle following transfer thethread unwinds from the new bobbin but is not completely threaded in theshuttle eye until the second pick of the shuttle. On the first shuttleflight after replenishment the weft is ordinarily under less tensionthan it is on subsequent picks of the shuttle.

It has been proposed heretofore to provide shuttle eyes which areintended to cause the tension on the first pick of the shuttle aftertransfer to be the same as on subsequent picks. Such shuttles may have aprimary tension which acts on the weft for all flights of the shuttleand a secondary tension which acts on the weft only on the pickimmediately following replenishment but as ordinarily made the secondarytension continues to have some effect on the tension of the weft afterthe shuttle is fully threaded.

It is an important object of the present invention to provide a shuttlehaving primary and secondary tensions and a guide post for the weftbeyond the secondary tension with respect to the primary tension. On thesecond pick after transfer the weft is drawn away from the secondarytension to a position entirely clear of it and bends around the guidepost and then extends to the delivery eye. The guide post and deliveryeye produce a tension effect equal to that of the secondary tension sothat all picks are under the same tension.

It is a further object of the invention to provide a secondary tensionwith two tension members one of which is located wholly above and theother behind the path which the weft traverses on the second andsubsequent picks.

It is another object of the invention to provide a secondary tension soconstructed that one of the tension members at least will have ahorizontal surface which partially closes the thread passage of theshuttle eye to prevent upward escape of the weft from the shuttle.

In order that the invention may be clearly understood reference is madeto the accompanying drawings which illustrate by way of example twoembodiments of the invention and in which:

Fig. 1 is a plan view of part of a shuttle having the invention appliedthereto,

Fig. 2 is a partial vertical section on line 22, Fig 1,

Fig. 3 is an enlarged horizontal section on 1i ne 3-3, Fig. 2,

Fig. 4 is an enlarged vertical section on line 4-4, g.

Fig. 5 is a perspective view showing the two parts of the secondarytension separated and in a position which they might occupy beforeassembly in the shuttle eye.

Figs. 6 and 7 are diagrammatic views showing the path of the weft on thefirst and second picks of the shuttle immediately following a weftreplenishing operation,

Fig. 8 is a diagrammatic view similar to Figs. 6 and 7 but showing amodified form, and

Fig. 9 is a view showing a second modified form in which the third guidepost is on the front secondary tension member.

The shuttle S may have many of the ordinary features characteristic ofself-threading shuttles employed in weft replenishing looms such as abobbin tip 1 and a bobbin compartment 2 for a bobbin B provided with aweft supply W. The shuttle is provided with a cavity 3 which receives ashuttle block 4 having front and back walls 5 and 6 respectively betweenwhich is a thread passage 7 extending lengthwise of the shuttle. In thatpart of the shuttle eye near the bobbin compartment 2 is located aprimary tension PT comprising in the present instance inner and outerpairs of tension pads 8 and 9. These pads may be of the usual type andextend vertically in the thread passage and are urged toward each otherby springs 10. The lower ends of the pads 8 and 9 are guided bytransverse pins 11 fixed to the shuttle. The usual adjustment for thesprings 10 is afforded by screws 12 threaded into the shuttle block. Theinvention is not limited to the use of the two pairs of pads 8 and 9since any form of primary tension can be used such for instance as asingle pair of pads. The two pairs are shown herein because theinvention has been adapted more particularly for use with elastic weftssuch as cotton covered rubber and it is desirable to have suflicienttension at the primary tension to maintain the stretched condition ofsuch weft.

The forward part of the shuttle is provided with a delivery eye D at thesides of which are the usual right and left tension posts 15 and 16respectively. These posts may be supported in fixed position on theshuttle in any approved manner and they are spaced lengthwise of theshuttle as suggested in Figs. 1 and 3. There is the usual thread passage17 between the metallic part f t e bl k 4 and t e ad acent part 18 ofthe Wood of the shuttle and the block has a downwardly and forwardlyextending horn 19 of the usual construction forward of the threadpassage. The shuttle body also has a shallow groove 20 extending towardthe adjacent tip end of the shuttle and the block may be held in fixedpos t on in the opening 3 by any approved means not shown herein.

In the operation of the part of the shuttle thus far descr bed thethread W passes between the pairs 8 and 9 of p ds and then extendsforwardly to the delivery eye and from the delivery eye will extendeither to the ri ht o the left. depending upon the direction in whichthe shuttle is moving. On the first pick after replenishing operationthe thread w ll extend in a re atively high posit on as s own in thedotted lines l-L Fig. 2, along the groove 2!) to the ma azine threadholder (not shownl and on the return fli ht of the shuttle the thread isdeflected downwardly and forwardly by the horn 19 so that it may enterthe passage 17 and the delivery eye D and be in the lower positionshownin dot and dash lines L. The matter thus far described may be ofusual construction and operate in the usual manner.

In carrying the present invention into effect the shuttle is providedwith a secondary tension ST and also with a third guide and tension postsomewhat similar to the posts 15 and 16 but in back of the latter. Thesecondary tension includes front and back vertically extending tensionmembers 26 and 27 respectively, the front member 26 as shown in Fig.having a rounded surface 28 to fit into a semi-cylindrical upwardly andrearwardly cylindrical pocket '29 formed in the shuttle block 4. By

means of a holding screw 30 the member 26 is held in its pocket in fixedposition with respect to the block. The member 26-has a rearwardlyfacing vertical flat tension surface 31 extending into passage 7.

The second vertical tension member 27 is longer than the front member'26 and extends downwardly as at 32 and is perforated as'at 33 toreceive a guide pin 34 below'member 26 extending transversely of andsecured in the shuttle. The upper part of the rear tension member isbent'rearwardlyas zit 35 and fits into an opening: 36 in the block 4; Acompression spring 37 normally urges the rear member 27 forwardlyagainst the flat surface 31 and a'screw 38 threaded: into the blockprovides means for varying the force exertedby the spring 37'. The lineof action of spring 37; as isapparent in Fig. 5', is intermediate thetop and bottom ofthe vertically extending surface 31'; The rear member27 may in fact be very similar to the tension members employed in' thepairs 8 and 9 of'pads in the primary tension. Thetop surface 40 ofthe'forward' vertical member 27 is inclined downwardly and rearwardly asshown for instance in Fig. 5 to form a threaded receiving notch 41.

Theguide post 25 is held fixed in the block and is between the secondarytension and the horn 19. It is also located forward of'surface 31 infront of a line joining the pads 9 and the member 27 so that any threadwhich is bent forwardly around it will be forward of the longer member27.

In operation, and assuming that the shuttle is in flight after justhaving been replenished with a full bobbin B, its thread will extend tothe thread holder (not shown) and will occupy the relatively highposition shown at'H in Fig. 2' and will be between both the primarytension pads 8 and 9 and also be'tween the vertical members 26 and 27of'the secondary tension, seeF'g. 6. The tension on this first pick istherefore determined by the primary and secondary tensions. When theshuttle is picked back in the reverse. direction the thread will bedeflected downwardly by the horn 19 which is a means for lowering thethread and the thread then enters the passage 17 and comes out of thedelivery eye D between the posts 15 and 16. When the thread is thusdisposed it is below the member 26 and forward of the surface due to thelocation of the third post 25, see Fig. 7. When in this position thepath reversed by the weft is entirely clear of the members 26 and 27 andthe tension is determined by the primary tension PT and also thefriction offered to movement of the thread by the post 25 and one or theother of the posts 15 or 16, depending upon the direction of travel ofthe shuttle. This tension is the same as the predetermined tension whichhad been produced on the first pick of the shuttle by the primary andsecondary tensions.

In Fig. 4 it will be seen that the member 26 has a horizontal bottomsurface 45 which extends over the weft W and since the surface 31 is inclose engagement with the surface 46 of the rear member 27 there is nochance for the weft to pass upwardly and become again engaged betweenthe members 26 and 27. As can be seen in Fig. 4, the lower end 32 andthe bottom surface 45 cooperate with each other and the thread block 4to form a closed passageway for the thread W to prevent the latter fromescaping from the shuttle block while at the same'time being inefiectiveto influence the tension of the thread. In the modified form shown inFig, 8 all of the parts already described will be substantially the sameexcept thatguide post 25a is between the primary and secondary tens-onsand also forward of surface 31, In the forrn shown in Fig. 9 the post25b, similar to po st 25,

. is fixed directly to and depends from the front tension 4; member 26,being also forward of surface 31 and to one side of the guide pin 34.

From the foregoing it will be seen that the invention sets forth ashuttle tension comprising a primary tension which is operative on thethread for all picks of the shuttle and a secondary tension which isoperative on only the first pick following weft replenishment. When theshuttle becomes completely threaded on its return or reverse flight thethread moves downwardly entirely clear of the secondary tension and thestationary posts 25, 25a or 25b and one of the other of the posts 15, 16will by friction produce a tension equal to that caused by the secondarytension.

Having now particularly described and ascertained the nature of theinvention and in what manner the same is to be performed, what isclaimed is:

1. In a self-threading shuttle having a thread delivery eye and a pairof thread guide posts associated with and defining part of said eye, athread block provided with a thread passage and a substantiallysemi-cylindrical upwardly'andrearwardly opening cylindrical pocketcommunicating with said passage at oneend thereof, primary tensioningmeans located in and at the other end of said passage, secondarytensioning means including a substantially cylindrical member snuglyfitting said pocket stationarily with respect to said block and having arearwardly facing vertical flat tension surface extending into saidpassage, said secondary tensioning means also including a verticallyextending tension member having a forwardly facing vertical flat tensionsurface for yielding engagement with sa'd first-mentioned surface andmovable. with respect to said block and said cylindrical membertransversely of said passage, both tensioning means cooperating witheach other to produce a predetermined tension on the thread on the firstpick of the shuttle after weft replenishment thereof, a flat bottomsurface on said cylindrical member above the bottom end of saidvert'cally extending tension member to prevent upward movement of thethread to a position between said members, holding means supporting saidcylindrical member in fixed position on the shuttle with said bottomsurface above the bottom of the thread passage, means on the shuttleeffective to move the thread downwardly and out of engagement with thesecondary tensioning means on the next pick of the shuttle, and guidemeans including a third guide post effective on said next and subsequentpicks to direct the thread along a path below and under said fiatsurface of said cylindrical member and forward of said verticallyextending tension member thereby causing the thread to be out of contactwith both of said members when in said path, the primary tensioningmeans cooperating with sa'd third post and one or the other of said pairof posts, depending upon the direction of travel of the shuttle, tomaintain the thread in said path and to produce said predeterminedtension on subsequent picks of the shuttle.

2. The shuttle set forth in claim 1 wherein said cylindrical member hasa downwardly and rearwardly inclined flat top surface to form a threadreceiving notch with said vertically extending tension member.

3. The shuttle set forth in claim 1 wherein the vertically extendingtension member is longer than and extends below said bottom surface ofsaid cylindrical member and has the lower end thereof guidingly mountedon a transverse pin fixed to said block and extending across saidpassage below said cylindrical member and said path, said lower end andsaid bottom surface coacting with each other and said block to form aclosed passageway for the thread.

4. The shuttle set forth in claim 1 wherein said thread block adjustablymounts a single spring for engagement with said extending tension memberto act along a line intermediate the top and bottom of said tensionsurfaces to urge the tension member against said cylindrical member topartially close said thread passage to prevent upward movement of thethread out of said passage.

5. The self-threading shuttle set forth in claim 1 wherein said guidemeans is a cylindrical post beyond the secondary means with respect tothe primary means and forward with respect to said rearwardly facingsurface to permit the thread to pass beneath said bottom surface to saidpath.

6. The self-threading shuttle set forth in claim 1 wherein said guidemeans is between said primary and secondary tensioning means and forwardof said rearwardly facing surface.

7. The self-threading shuttle in claim 1 wherein the guide means isfixed to and depends from said bottom surface forward of said rearwardlyfacing surface.

References Cited in the file of this patent UNITED STATES PATENTS2,125,405 Tebo Aug. 2, 1938 2,288,960 Teague et a1. July 7, 19422,379,650 Nichols July 3, 1945 2,663,327 Carrigan Dec. 22, 1953

